Question

One third of total numbers of students in a class are in chemistry laboratory, one fourth is in physics laboratory, one sixth is in biology laboratory and 12 are in mathematics lab. How many students are there in the class?

Answer 1

Let us consider the total no. of students as X.

So:

1/3 of X + 1/4 of X + 1/6 of X + 12 = X

X/3 + X/4 + X/6 + 12 = X

4X + 3X + 2X + 144 / 12 = X

9X + 144 = 12X

9X - 12X = - 144

- 3X = - 144

X = 144/3 = 48 Nos.